1. Field of the Invention
The present invention pertains to an apparatus designed for down hole use during the production of hydrocarbons in an oil or gas well wherein means are provided to enable injecting chemical inhibitor against corrosion and the like within the well casing to the area immediate and below the well packer apparatus for subsequent circulation of the inhibitor with the produced hydrocarbon within well tubing inserted through the packer apparatus, to the well surface.
2. Description of the Prior Art
Corrosion of metallic production tubing and the like utilized in oil and gas wells is caused by numerous chemical factors and has been a problem of great concern to the industry. Heretofore, metallic tubing has been protected by circulating within the tubing-casing annulus a chemical corrosion inhibitor, the chemical formulation of which has varied throughout the years with improvements in the art. The utilized inhibitor generally is made up through emulsification with water or diesel oil and is circulated within an aqueous system down the tubing-casing annulus, thence upwardly above the packer in the produced hydrocarbon stream from the production zone of the well. Although advantageous and affording protection above the packing assembly, this concept and procedure has not afforded protection against and inhibition of corrosion of metallic tubing inserted through and projecting immediately below the lower end of the packer assembly. Therefore, this area is exposed to a potential corrosive environment without means of protection therefrom.
The present invention overcomes the problems resulting from use of prior art means for affording protection against corrosion of metallic tubing used during the production of hydrocarbons in an oil and gas well by providing means whereby the fluid inhibitor within the tubing-casing annulus is circulated through a valving apparatus and a circulation bypass for ejection below the lower end of the packer assembly, whereby the corrosion inhibitor solution is mixed with the produced hydrocarbon and circulated to the top of the well through the production tubing, the lower end of which is projected through the packer assembly. By use of the present invention, it is now possible to afford corrosion inhibition of metallic tubing as well as to provide means to dissolve salt in the production stream in the area below the packer assembly, as well as the casing and tubing inserted through the packer assembly. In this fashion, the complete internal and external diameters of the entire metallic tubing string are afforded exposure to the injected fluid by means of a complete corrosion protection circulation path.